In prior art parts washer systems, rubber flaps are used at the entrance and exit to the wash zone of the washer to isolate the wash zone from the surrounding environment and from subsequent parts washer zones. Usually, when a part is to be washed, it first goes through the wash zone, then perhaps a rinse zone, and finally a dryer. In the prior art, each of these zones were isolated from one another by such rubber flaps, or by other even less desirous means. These rubber flaps, comprising either a solid sheet or a series of slit sheets, attempt to confine fluid spray to the inside of a specific zone and to further retain the heat therein. The difficulty with such rubber sheets is that the different configuration of the parts being washed and their physical sizes, were constantly causing the rubber material to tear, thereby permitting fluid from the wash and rinse zones to combine, and allowing heat and water vapor to otherwise be dissipated. This has created problems in the cleaning and recharging of the supply tanks for each of the zones, and further resulted in high maintenance costs due to the need for rubber flap replacement.
Further, present rubber flap doors, even when not torn, only partially block heated air and vapor movement, especially when a part is in the process of moving past such a flap. At such times air and vapor are able to escape past the flaps. This is caused in part by the fact that the rubber flaps open considerably as parts on the continuous moving conveyor of a parts washer cause them to deflect. The wash spray typically found in a wash zone is quite hot. The efficiency of this wash zone in terms of energy wasted is substantially affected if much of this heat in the form of vapor is lost from the wash zone, instead of recycled therein. A recent energy study on a washer showed that greater than half of the washer's input energy was dissipated in vaporization loss. Similarly, vapor that is allowed to escape into a dryer zone would make drying of the parts that much less efficient.